1. Field of Invention
This invention relates to apparatus for covering a large land area with a long length, wide width heavy flexible sheeting, such as a geotextile clay liner.
2. Description of Prior Art
There are many artificial landfills that are excavated from sand, gravel, clay and other natural raw materials. The purpose for the different excavations is usually to serve as landfill dump sites for rubbish such as trash, garbage, and other waste materials. The excavations have also been used to receive the residue or refuse of the cleaning of mined products such as coal. As the artificial, excavated dump sites evolved the environmental regulatory rules and regulations governing their use became more strict and more complex, in an effect to prevent their causing more problems than they sought to solve. It has become a regulatory requirement that refuse dump sites be so constructed and formed that none of the materials that might arise from their contents could in any way seep into and pollute the surrounding environment. A typical regulatory requirement calls for lining the dump sites with an impervious liner or sheeting to prevent seepage of contaminants into the underlying ground. A typical liner would be a flexible geosynthetic or geotextile clay liner (GCL) which usually comes in a large heavy roll about 12-16.5 feet wide to about 135-150 feet long, weighing about 2200 to 3200 pounds. The GCL is, in essence, a sandwich of bentonite clay between two layers of heavy duty, flexible synthetic resin fabric. The liners are laid directly onto the ground formation surface with an overlap as required by the regulations. Theoretically, the laying of the liner would be accomplished by the simple means of threading the heavy roll of GCL onto a support rod, securing the support rod on a rigid beam, fixing the beam to a powered construction vehicle, carrying the roll along the dump site allowing the sheet liner to pay out and lay on the ground surface.
Typical dump sites range in size from about 6 acres to as large as about 450 acres and being as deep as around 380 feet. The sides if the dump site basin are typically sloped with so-called anchor trenches formed in them for receiving the flexible liners for securing them in place on the slopes. Abutments may also be formed on the surface of the dump site basin.
Various systems have been designed to lay out the GCL all including threading the roll onto a support rod fixed on a rigid beam and pulling the beam and rod to lay out the liner. One such device is that described in U.S. Pat. No. 6,264,400 of Keith A. Gent which includes in his assembly a long beam or framework which is attached behind a tractor clear of the ground, the beam having end plates between which are borne a support rod for carrying a roll of liner material such as GCL. The structure of the Gent device is somewhat complex and is clearly intended to be mounted to the rear of a tractor. The Gent device includes control means for adjusting the lateral angle of linkages secured to the framework for moving the roll of liner material to either side. A drawback of the Gent device that it could not be used in an excavation where maintaining the subgrade is important. Useable only with a tractor would require the tractor to travel over the subgrade and, in effect, destroy it. The Gent device would also require the tractor to move over anchor trenches and abutments, which would avoid proper placement of the liner as well as destroying the abutments. Similar to the Gent device is that described in U.S. Patent Application 2004/0161300 to Joseph B. Kaul et al which includes a complex arrangement of a pair of powered cradle rollers arranged to receive and disperse a heavy roll of liner sheeting such as GCL. As with the Gent device, the device of Kaul et al is arranged on the rear of a tractor requiring the tractor with the device to travel over subgrades, anchor trenches and abutments, destroying or deteriorating the subgrades and abutments and avoiding proper placement of the liner. Another drawback the Gent and Kaul et al devices is that they require another vehicle, such as a forklift, to place the rolls of liner material onto the rollers of the respective devices. Worker or workers would be needed for handling the rolls of liner material and placing them onto the arbors of the devices, creating a safety hazard for pinched fingers and such like, as well as requiring time consuming operations by the workers such as guiding the arbors into bearings, securing the arbors in the bearings, and latching them in place.
Another device for laying sheeting on a ground surface is that of U.S. Pat. No. 5,304,014 to John D. Slutz. This device is somewhat similar to those of Gent and Kaul et al including a complex framework arrangement adapted for mounting engagement on the rear of a construction vehicle such as a tractor. The Slutz device includes a pair of transversely extending arms which carry a journalled arbor assembly between them. The arbor assembly includes a mandrel for supporting a roll of liner material. A drive mechanism serves to apply a rotational motion to the mandrel for either unrolling or rolling the liner off or back onto the mandrel No provision is made for laterally positioning the liner for overlapping liners where required. As with the Gent and Kaul et al devices, the Slutz device would be driven by a tractor over subgrade, anchor trenches, and abutments, destroying the subgrades and abutments, and avoiding proper placement of this liner. Also, as with the previously described devices, the Slutz device would require a separate vehicle, such as a forklift and assisting workers, for safety hazard and time consuming loading and securing rolls of liner. The Slutz device is also intended to cover landfill sites when they are not being worked and to take up the sheeting material when it is desired to work the area. Slutz does not suggest the use of GCL or other heavy liner sheeting.
The device of U.S. Pat. No. 7,494,301 to Daniel J. Neaton is for laying an erosion control blanket on a sloping bank of a land site. A lightweight flexible blanket, unlike heavy GCL, is carried on a spindle cantilevered on a support structure communicating with a hydraulic rotary actuator. The support structure is secured to the front end of a track loader or the like. Neaton does not suggest structure for carrying and dispensing heavy liner sheeting, nor is provision made or structures provided for the overlapping of liner sheeting. As with all of the previously described devices the Neaton device would move its lightweight sheeting over subgrades, anchor trenches, and abutments destroying or deteriorating the subgrades and abutments, and avoiding proper placement of heavy liner sheeting.
The devices of U.S. Pat. No. 5,536,116 to Arville Lammers et al, U.S. Pat. No. 6,558,080 to Randall Jeff Kozak, and U.S. Pat. No. 6,299,094 to Forrest Hood James, Jr., are all somewhat similar in structure to the previously described devices and have the same drawbacks. Each device would require travel over subgrades, anchor trenches, and abutments; would necessitate the need of a separate vehicle such as a forklift to load a roll of liner onto an arbor; would require a worker or workers for assisting the loading and securing the rolls in place on a mandrel or spindle. Additionally, the devices of Lammers and Kozak are arranged for spreading material over this sheeting after it is laid out with Lammers using a compactor which would destroy the subgrade. The Lammers, Kozak, and James, Jr. devices are not constructed for laterally moving the liner roll and cannot overlap the sheeting.
The apparatus for covering a large land area with a heavy, flexible sheeting of the present invention overcomes the problems inherent in known designs of devices for laying liners or sheeting on ground surfaces. The liner laying apparatus of the present invention is arranged to be secured to the working arm, so-called crowd, of an excavator and allows precise placing of a heavy, wide width, flexible sheeting, such as GCL, on a land area without it being driven over subgrade, anchor trenches, or abutments. The apparatus (device) of the present invention allows liners to be overlapped without having to precisely guide the course of the excavator. Additionally, the device of this invention does not require a separate vehicle to load a roll, and is, in effect, self-loading, nor does it require a worker or workers to load the roll or secure it in place, making it safe against injuries since no person needs to touch the rolls or the device itself. As well as being safe in its use, the loading and unloading is efficient taking very little time. Also, the device of this invention used with an excavator is useable in difficult areas where tractors, skid steer vehicles, and such like vehicles cannot travel and lay liner sheeting.